scholarly journals The loop-mediated isothermal amplification technique to determine T. gondii infection in women with spontaneous abortion

2019 ◽  
Author(s):  
Farnaz Kheirandish ◽  
Shirzad Fallahi ◽  
Hossein Mahmoudvand ◽  
Khatereh Anbari ◽  
Ali Araban ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Spontaneous Abortion ◽  
Serological Test ◽  
Isothermal Amplification ◽  
Toxoplasma Infection ◽  
Igg Antibody ◽  
Serological Tests ◽  
Loop Mediated Isothermal Amplification ◽  
Igm Antibody ◽  
Significant Difference

Abstract Background Toxoplasmosis caused by Toxoplasma gondii is well-known as one of the most widespread parasitic diseases, which has now infected nearly a third of the world's population. Among the infectious agents, T. gondii is considered as one of the main causes of spontaneous abortion (SA). The present study aimed to use the loop-mediated isothermal amplification (LAMP) technique in comparison with serological tests to determine the rate of T. gondii infection in women suffering from SA in Lorestan Province, Western Iran. Methods A total of 140 women suffering from their first spontaneous abortion and who had been referred to the Obstetrics and Gynecology Department, Asalian hospital (Khorramabad, Iran) were included in this study. The collected aborted fetal remains and blood samples (5 ml) from each patient were examined in sterilized conditions using the LAMP technique and ELISA commercial kits to determine the specific IgM and IgG anti-Toxoplasma antibodies respectively. Moreover, a questionnaire about some demographic and risk factors, such as the mother’s age, gestational age, and contact with cats was completed for each patient. Results Of the 140 women, 80 (57.1%) tested seropositive for anti-T. gondii antibodies by ELISA, 72 (51.4%) women tested seropositive for the IgG antibody, 8 (5.7%) tested seropositive for the IgM antibody. Among the 8 women who’d had their first spontaneous abortion who tested seropositive for IgM antibody by ELISA, only 5 cases (62.5%) reported positively to the LAMP test. The difference in the frequency distribution of the LAMP results for measuring the Toxoplasma infection in pregnant women under study was statistically significant (P <0.001) from the results of the serological test (ELISA). Although there was a significant difference between age and positivity in the LAMP test (P = 0.017), no significant difference was observed between positivity in the LAMP test and residence, education, job, and contact with cats. Conclusion The findings of the present investigation suggest that LAMP is a preferred method for determining Toxoplasma infection in pregnant women suffering from spontaneous abortion compared with other routine serological tests.

scholarly journals Reliability of serological tests for COVID-19: Comparison of three immunochromatography test kits for SARS-CoV-2 antibodies

2020 ◽  
Author(s):  
Hidetsugu Fujigaki ◽  
Masao Takemura ◽  
Michiko Osawa ◽  
Aki Sakurai ◽  
Kentaro Nakamoto ◽  
...  
Keyword(s):  
Early Stage ◽  
Serological Test ◽  
Entire Period ◽  
Serum Samples ◽  
Igg Antibody ◽  
Serological Tests ◽  
Igm Antibody ◽  
Potential Clinical Utility ◽  
Almost All ◽  
Positive Results

AbstractBackgroundSeveral immunochromatographic serological test kits have been developed to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies, but their relative performance and potential clinical utility is unclear.MethodsThree commercially available serological test kits were evaluated using 99 serum samples collected from 29 patients diagnosed with coronavirus disease 2019 (COVID-19).ResultsThe IgM antibody-positive rates of the three serological test kits for samples taken at the early stage of the disease (0–6 days after onset) were 19.0%, 23.8%, and 19.0%, respectively. The IgM antibody-positive rates over the entire period were 21.2%, 60.6%, and 15.2%, respectively. The IgG antibody-positive rates for samples taken after 13 days of onset were 100.0%, 97.6%, and 97.6%, respectively.ConclusionThere were large differences among the results of the three test kits. Only few cases showed positive results for IgM in the early stage of disease and the IgM antibody-positive rates over the entire period were low, suggesting that the kits used in this study were unsuitable for diagnosis of COVID-19. The IgG antibody was positive in almost all samples after 13 days of onset, suggesting that it may be useful for determining infections in the recent past.

scholarly journals Development and Clinical Evaluation of Loop-Mediated Isothermal Amplification (LAMP) Assay for the Diagnosis of Human Visceral Leishmaniasis in Brazil

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Daniel Moreira de Avelar ◽  
Débora Moreira Carvalho ◽  
Ana Rabello
Keyword(s):  
Visceral Leishmaniasis ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Health Concern ◽  
Serological Tests ◽  
Blood Samples ◽  
Loop Mediated Isothermal Amplification ◽  
Human Visceral Leishmaniasis ◽  
Highly Sensitive ◽  
Sensitivity Specificity

Visceral leishmaniasis (VL) is considered a major public health concern in Brazil and several regions of the world. A recent advance in the diagnosis of infectious diseases was the development of loop-mediated isothermal amplification (LAMP). The aim of this study was to develop and evaluate a new LAMP assay for detection of K26 antigen-coding gene of L. donovani complex. A total of 219 blood samples of immunocompetent patients, including 114 VL cases and 105 non-VL cases, were analyzed for the diagnosis of VL in the present study. Diagnostic accuracy was calculated against a combination of parasitological and/or serological tests as a reference standard. The results were compared to those of kDNA Leishmania-PCR. The detection limit for the K26-Lamp assay was 1fg L. infantum purified DNA and 100 parasites/mL within 60 min of amplification time with visual detection for turbidity. The assay was specific for L. donovani complex. Sensitivity, specificity, and accuracy were 98.2%, 98.1%, and 98.2%, respectively, for K26-LAMP and 100%, 100%, and 100%, respectively, for kDNA Leishmania-PCR. Excellent agreement was observed between K26-LAMP and kDNA Leishmania-PCR assays (K = 0.96). A highly sensitive and specific LAMP assay targeting K26 antigen-coding gene of L. donovani complex was developed for diagnosis in peripheral blood samples of VL patients.

scholarly journals Specific immunoglobulin responses in serum and nasal secretions after the administration of attenuated rubella vaccine

1974 ◽  
Vol 73 (1) ◽  
pp. 127-141 ◽  
Author(s):  
J. E. Cradock-Watson ◽  
Helen Macdonald ◽  
Margaret K. S. Ridehalgh ◽  
M. S. Bourne ◽  
Elise M. Vandervelde
Keyword(s):  
Serum Antibody ◽  
Adult Women ◽  
Igg Antibody ◽  
Rubella Vaccine ◽  
Igm Antibodies ◽  
Igm Antibody ◽  
Significant Difference ◽  
Specific Immunoglobulin ◽  
Iga Response ◽  
Iga Antibody

SUMMARYThe indirect immunofluorescent technique has been used to study the specific immunoglobulin responses in the sera of 63 non-immune adult women who received either Cendehill rubella vaccine subcutaneously, RA27/3 rubella vaccine subcutaneously, or RA27/3 vaccine intranasally. IgG, IgA and IgM antibodies increased virtually simultaneously, starting about 2 weeks after vaccination. IgG antibody appeared in all subjects and reached maximum titres 4–6 weeks after vaccination. The mean IgG titres elicited by the three different methods of vaccination did not differ significantly. IgA and IgM antibodies reached their highest titres between 21 and 28 days after vaccination and then declined to low or undetectable titres within about 9 weeks. The maximum IgA titres observed after intranasal administration of RA27/3 vaccine were significantly higher than those which occurred when the same vaccine was given subcutaneously, but no significant difference in IgM titres was observed. When unfractionated sera were examined IgA antibody was detected in 57 cases (91%) and IgM in 51 (81%). Fluorescent examination of fractions obtained by centrifugation on sucrose density gradients frequently revealed small amounts of IgA and IgM antibody which could not be detected by staining unfractionated serum, and with the inclusion of these results IgA antibody was detected in 61 cases (97%) and IgM in 59 (94%).When 39 adults with pre-existing serum antibody were challenged with vaccine a definite IgA response was detected in only one subject and in no case was there any evidence of the appearance of IgM antibody.Nasal antibody, consisting of IgG or IgA or both, was detected in 17 out of 23 non-immune subjects (74%) who received RA27/3 vaccine, either subcutaneously or intranasally. Titres were much lower than those which occur in the natural disease and there was no evidence that nasal antibody was elicited more readily by intranasal than by subcutaneous vaccination.

scholarly journals The antibody response in Legionnaires' disease

1979 ◽  
Vol 83 (2) ◽  
pp. 377-381 ◽  
Author(s):  
J. Nagington ◽  
T. G. Wreghitt ◽  
J. O'H. Tobin ◽  
A. D. Macrae
Keyword(s):  
Antibody Response ◽  
Serological Test ◽  
Igg Antibodies ◽  
Immunofluorescence Technique ◽  
Igg Antibody ◽  
Recent Infection ◽  
Igm Antibody ◽  
Serotype 1 ◽  
Indirect Immunofluorescence Technique ◽  
Legionnaires Disease

summaryFrom 22 patients with Legionnaires' disease, 86 sera were examined for specific serotype 1 IgM and IgG antibodies by the indirect immunofluorescence technique.No antibody was detectable until 8 days or more from the onset of symptoms. When produced the amount was widely variable and remained detectable for periods from less than 34 days to more than 1 year.Initially IgM antibody predominated, ten patients produced only IgM in the first 21 days, six produced only IgM in the first 28 days and three did not produce IgG at any time. One patient, and possibly a second, produced only IgG antibody.Since IgM antibody was still present in one patient after a year it is important not to accept the presence of this as evidence of very recent infection.It is advisable that any type of serological test for L. pneumophila infection should detect the production of both IgM and IgG antibodies.

scholarly journals The role of serological tests and biopsy in the diagnosis of celiac disease: retrospective review of 1137 duodenal biopsies

2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Feridun Gurlek ◽  
Eyyup Tasdemir ◽  
Taskın Erkinuresin
Keyword(s):  
Celiac Disease ◽  
Serological Test ◽  
Young Female ◽  
Duodenal Biopsy ◽  
Gluten Sensitivity ◽  
Biopsy Result ◽  
Serological Tests ◽  
Number Of Patients ◽  
Significant Difference ◽  
Duodenal Biopsies

Background: The aim of this study is to evaluate gluten sensitivity and/or celiac disease (CD) on the basis of serological tests and duodenal biopsy and to draw attention to the prevalence in the population and the correlation between serological tests and biopsy results.Methods: Patients who applied to Health Sciences University Bursa High Specialization Training and Research Hospital between 2015-2019 and who underwent serological tests and duodenal biopsies with a diagnosis of CD or gluten sensitivity were retrospectively analyzed.Results: The study was conducted with a total of 1137 cases, 61.2% (n = 696) of who were women and 38.8% (n = 441) were men. Their ages range from 17 to 91, with a mean of 40.16 ± 16.18 years. Of the 178 patients with gluten sensitivity, 122 (68%) were female and 56 (32%) were male. According to the results of duodenal biopsy, an average of 8% Marsh 3, 5% Marsh 1-2 was detected in the last five years. For the whole study, a significant difference was found between celiac autoantibody positivity rates according to the biopsy results (p = 0.001; p <0.01). The rate of serological test positivity was higher in patients with biopsy result Marsh 3 than those with normal biopsy result, peptic duodenitis and Marsh 1 and 2. No statistically significant difference was found between the rates of Marsh 3 biopsy results and serological test positivity by years (p> 0.05).Conclusions: The number of patients applied with a diagnosis of CD in the last five years has gradually increased (3.4-33.7%). Of the patients with Marsh 3 and Marsh 1-2 biopsy results, 78% were under 50 years old. This suggests that gluten enteropathy in young female patients having digestive system complaints should not be ignored during the diagnosis. Serological test results were highly correlated with the biopsy results in patients with Marsh 3 biopsy results. We think that if clinical findings are supported with serological tests and directed for biopsy in the diagnosis of celiac disease, it will be more cost effective and the workload and time loss will be prevented.

scholarly journals Seroprevalence of anti-SARS-CoV-2 IgG antibodies in Juba, South Sudan: a population-based study

2021 ◽  
Author(s):  
Kirsten E. Wiens ◽  
Pinyi Nyimol Mawien ◽  
John Rumunu ◽  
Damien Slater ◽  
Forrest K. Jones ◽  
...  
Keyword(s):  
Test Performance ◽  
Serological Test ◽  
South Sudan ◽  
Bayesian Regression ◽  
Sub Saharan Africa ◽  
Surveillance Systems ◽  
Igg Antibody ◽  
Serological Tests ◽  
Cross Sectional ◽  
Sub Saharan

AbstractBackgroundRelatively few COVID-19 cases and deaths have been reported through much of sub-Saharan Africa, including South Sudan, although the extent of SARS-CoV-2 spread remains unclear due to weak surveillance systems and few population-representative serosurveys.MethodsWe conducted a representative household-based cross-sectional serosurvey in Juba, South Sudan. We quantified IgG antibody responses to SARS-CoV-2 spike protein receptor-binding domain and estimated seroprevalence using a Bayesian regression model accounting for test performance.ResultsWe recruited 2,214 participants from August 10 to September 11, 2020 and 22.3% had anti-SARS-CoV-2 IgG titers above levels in pre-pandemic samples. After accounting for waning antibody levels, age, and sex, we estimated that 38.5% (32.1 - 46.8) of the population had been infected with SARS-CoV-2. For each RT-PCR confirmed COVID-19 case, 104 (87-126) infections were unreported. Background antibody reactivity was higher in pre-pandemic samples from Juba compared to Boston, where the serological test was validated. The estimated proportion of the population infected ranged from 30.1% to 60.6% depending on assumptions about test performance and prevalence of clinically severe infections.ConclusionsSARS-CoV-2 has spread extensively within Juba. Validation of serological tests in sub-Saharan African populations is critical to improve our ability to use serosurveillance to understand and mitigate transmission.

scholarly journals Longitudinal Change of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies in Patients with Coronavirus Disease 2019

2020 ◽  
Vol 222 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Guoxin Zhang ◽  
Shuke Nie ◽  
Zhaohui Zhang ◽  
Zhentao Zhang
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Disease Onset ◽  
Immunoglobulin M ◽  
Longitudinal Change ◽  
Igg Antibody ◽  
Serological Tests ◽  
Significant Difference ◽  
Rapid Spread ◽  
Novel Coronavirus ◽  
Acid Test

Abstract Background A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently emerged and caused the rapid spread of coronavirus disease 2019 (COVID-19) worldwide. Methods We did a retrospective study and included COVID-19 patients admitted to Renmin Hospital of Wuhan University between 1 February and 29 February 2020. Antibody assay was conducted to detect COVID-19 envelope protein E and nucleocapsid protein N antigen. Results One hundred twelve patients were recruited with symptoms of fever, cough, fatigue, myalgia, and diarrhea. All patients underwent antibody tests. Fifty-eight (51.79%) were positive for both immunoglobulin M (IgM) and immunoglobulin G (IgG), 7 (6.25%) were negative for both antibodies, 1 (0.89%) was positive for only IgM, and 46 (41.07%) were positive for only IgG. IgM antibody appeared within a week post–disease onset, lasted for 1 month, and gradually decreased, whereas IgG antibody was produced 10 days after infection and lasted for a longer time. However, no significant difference in levels of IgM and IgG antibodies between positive and negative patients of nucleic acid test after treatment was found. Conclusions Our results indicate that serological tests could be a powerful approach for the early diagnosis of COVID-19.

Antithyroid Antibodies in Sera of Women with Spontaneous Abortion and Normal Pregnancies

2020 ◽  
Vol 70 (12) ◽  
pp. 4326-4331
Keyword(s):  
Autoimmune Disease ◽  
Pregnant Women ◽  
Pregnancy Outcome ◽  
Spontaneous Abortion ◽  
Autoimmune Thyroiditis ◽  
Normal Pregnancy ◽  
Thyroid Antibodies ◽  
Outcome Group ◽  
Significant Difference ◽  
Group A

Autoimmune thyroiditis is the most frequent autoimmune disease. We analyzed the association between the presence and value of titer of anti-thyroid antibodies (atbs) and spontaneous abortion (SA). Moreover, we analyzed the association between TSH values and the presence of anti-thyroids atbs. We tested anti-TPO and anti-TG atbs in 257 women: 85 probands, 87 pregnant women with normal pregnancy outcome, and 85 with SA. We tested TSH in 87 pregnant women with normal pregnancy outcome. No significant difference was found between the prevalence of cases with positive anti-TPO and anti-TG atbs in women with normal pregnancy outcome vs. SA patients. In women with positive atbs titer, anti-TPO and anti-TG values were higher in SA group compared with normal pregnancy outcome group. A significant threshold was reached only for anti-TG atbs. TSH values were higher in pregnant women with positive anti-TPO and anti-TG values compared with those with a negative atbs titer. In pregnant women with positive anti-thyroid atbs titers, spontaneous abortion group patients have higher anti-TG titers than women with normal pregnancy outcome. TSH values are higher in the group of patients with positive anti-TPO and anti-TG atbs titers compared with the group of patients with negative anti-TPO and anti-TG values. Keywords: Anti-TPO, anti-TG, pregnancy outcome, spontaneous abortion, TSH

scholarly journals Loop-mediated isothermal amplification: a rapid molecular technique for early diagnosis of Pseudomonas syringae pv. syringae of stone fruits

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
R. Goudarzi ◽  
M. M. Mortazavi
Keyword(s):  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Selective Medium ◽  
Isothermal Amplification ◽  
Plant Diseases ◽  
Molecular Technique ◽  
Specific Method ◽  
Stone Fruits ◽  
Serological Tests ◽  
Loop Mediated Isothermal Amplification

Abstract Background Pathogenic bacteria cause significant economic damages in agriculture. The detection of such bacteria is considered as a continual interest for plant pathologists to prevent disease dissemination. Pseudomonas syringae pv. syringae is one of the most important bacterial pathogens infecting yield and quality of stone fruits throughout the world. Biochemical assays such as a LOPAT and GATTa are common methods to detect this pathogen. Serological tests and culturing on King’s B selective medium also used to isolate this bacterium. Selective media is composed of specific and effective ingredients to inhibit the growth of certain species of microbes in a mixed culture while allowing others to grow. These are used for the growth of only selected microorganisms. King’s B medium can be used as a general medium for the non-selective isolation cultivation and pigment production of Pseudomonas species from foods, cosmetic samples, plants, etc. Nevertheless, the mentioned methods are not enough accurate to differentiate the strains. On the other hand, PCR-based techniques are sensitive and efficient in detecting plant diseases. However, these techniques are not practicable for those researchers who do not have access to a thermal cycler. We have used loop-mediated isothermal amplification to couple with a target. The amplification of syrD gene using loop and bumper primers can be used to prevent disease dissemination. Results The outcome of this investigation indicated more sensitivity of LAMP in comparison to PCR. The direct addition of SYBR Gold in microtube is more sensitive than gel in both LAMP and PCR byproducts so we can eliminate gel electrophoresis, while the LAMP showed high sensitivity and high specificity in comparison to results obtained by cultivation. The described molecular test could detect Pseudomonas syringae pv. syringae type in nearly 1 h, and this is the first time that Lamp molecular detection of Pseudomonas syringae pv. syringae particularly on stone fruits is described and introduced. Conclusions The obtained data confirmed that LAMP is a fast, cheap, and high specific method for the rapid detection of Pseudomonas syringae pv. syringae to the comparison of PCR and culture.

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